Mast structure and method of erection



H. J. WOOLSLAYER ET AL 2,363,106

MAST STRUCTURE AND METHQD OF ERECTIQN 2 Shets-Sheet 1 Filed Jan. 10, 1944 Q Q V VfiTNESSES: W4, Wm

BY [Om wauwr Ma fie)? ATTORNEYS.

Nov. 21, 1944.

H. J. WOOLSLAYER ETAL 2,363,106

MAST STRUCTURE AND METHOD OF ERECTION Filed Jan 10, 1944 2 Sheets-Sheet 2 Patented Nov. 21, 1944 MAST STRUCTURE AND METHOD OF ERECTION Homer J. Woolslayer, Erwin A. Campbell, and Cecil Jenkins, Tulsa, Okla, assignors to Lee C. Moore & Company, Inc., Pittsburgh, Pa., a corporation of Pennsylvania Application January 10, 1944, Serial No. 517,644

Claims.

This invention relates to masts or derricks, such as used with oil wells, that are adapted to be assembled in prone position along the ground from prefabricated sections and then swung upwardly into upright position.

In our Patent No. 2,332,479 we have pointed out some of the advantages of hinging the rear or upper legs of a prone mast to a base before swinging the mast into upright position, rather than hinging the front or lower legs to the base as had been the practice before. That patent discloses how such a desirable thing can be done when the base is elevated by a bifurcated substructure. In many cases, however, it would be desirable to use such a mast without a substructure, but that presents a problem that has not been solved heretofore because the lower ends of the upper pair of legs would be spaced above the base when the mast is in prone position.

It is among the objects of this invention to provide a method of raising a prone mast during which the upper legs of the prone mast are hinged to a low base, in which the mast lifting loads are not excessive, in which a relatively small and lightweight gin pole may be used, and in which excessive strain is not imparted to the legs of the gin pole adjacent the mast. Another object of this invention is to provide a mast structure in which the mast is capable of being raised by this method.

In accordance with this invention a mast is provided with front and rear pairs of stationary or rigidly connected legs, one pair of which terminates a substantial distance above the lower ends of the opposite pair. Extension legs are connected to the lower ends of the shorter legs in such a manner that during raising and lowering of the mast they can be moved out of the way. Thus, they may be swung out of the way or be completely removed from the mast temporarily. The mast is assembled along the ground and the lower ends of its shorter pair of legs are placed upon a supporting base that may also carry the draw-works. The top of the mast is then swung upwardly to rock the mast vertically on its base-engaging portion until the lower ends of its lbnger pair of legs have been lowered to the base. These legs are then hinged to the base, following which the top of the mast is raised further in order to lift the short leg-side of the mast from the base and to swing the mast into upright position. The extension legs are then moved into position and connected to the base so that the mast will be firmly supported. On the other hand, the extension legs can be omitted, in which case the upright mast can be supported by guy-lines or other suitable means.

Preferably, while the mast is being rocked toward upright position on its base-engaging portion its longer pair of legs are simultaneously forced down toward the base to aid in the rocking movement. This action maybe obtained by means of a gin pole mounted on the base and having front and rear legs connected together at the top. One pair of legs of the gin pole are pivotally connected to the base, while its opposite pair of legs are hinged to the lower ends of the masts longer pair of legs. Cable means, connected to a suitable hoist, enters the upper part of the mast and passes down through it and then up to the top of the gin pole. When the cable means is reeled in, it not only lifts the top of the mast, but also pulls down on the gin pole that therefore presses down on the mast legs to which it is connected.

The preferred embodiment of the invention is illustrated in the accompanying drawings in which Fig. 1 is a side view of our mast in its lowered or prone position extending along the ground; Fig. 2 is a side view showing the mast in partly raised or inclined position; Fig. 3 is a side view showing the mast in upright operative position; Fig. 4 is a fragmentary plan view of the lowered mast; and Fig. 5 is a fragmentary view of the rear side of the mast structure.

Referring to Fig. 1 of the drawings, a mast is assembled along the ground from a plurality of prefabricated sections I, 2, and 3. The mast will be described as being assembled with its front side down, but it will be understood that the same method can be followed if the rear side of the mast is against the ground. The two stationary front legs 4 of the mast are shorter than the stationary upper or rear pair of legs 5, with the front legs terminating a considerable distance above the lower ends of the rear legs. Preferably, a. pair of extension legs 6 are connected for universal movement to the lower ends of the front legs and these lower ends are placed in seats I mounted on the front end of a base 8 that rests upon the ground with the major portion of the mast lying on the ground in front of the base. The pivotally mounted extension legs may lie on the base, or they maybe swung up toward the rear legs and be temporarily fastened there. Of course, the extension legs could be disconnected from the front legs at this time, if desired. l

Mounted on'the base between its rear end and the bottom of the mast is the draw-works drum in which is straddled by an upwardly tapered gin pol having two front legs II and two rear legs I! and a cross member l3 (Figs. 4 and 5) at their upper ends. Each front leg is pivotally connected at its upper end to the leg behind it, and the lower ends of the rear-legs are hinged to the base by brackets l4 between drum l0 and the adiacent end of the base. The lower ends of the front legs of the gin pole are hinged by brackets to the lower ends of the rear legs of the mast.

As shown in Fig. 1, the lead line I! of the cable system of the mast extends from the drawworks up and around a pulley l8 mounted on cross member l3 of the gin pole, and then outwardly to the fast sheave l9 joumaled in the rear side of the upper end or the mast. The

line passes from the fast sheave back through the mast to the traveling block and then back again to the crown block 2| in the usual way. It is not necessary, however, that this line be connected to the draw-works nor pass over the gin pole, as it could be connected to a separate winch behind the base, or it could pass from the draw-works directly to sheave l9.

In order to erect the mast the traveling block is connected temporarily to a cable Sling which passes under pulleys 26, mounted in the mast, and up to the cross member of the gin pole to which it is attached. When drum I0 reels in the lead line, the sling is pulled up into the mast. .Due principally to the lifting effort of the sling, the outer or upper end of the mast is swung upwardly while the opposite end or foot of the mast swings downwardly because of the rocking of the mast in the seats 1 on the base. At the same time the forward pull of the cable sling on the top of the gin pole swings the gin pole forward, whereby the front legs of the gin pole exert a downward pressure on the lower ends of the rear legs of the mast until they reach the supporting base as shown in Fig. 2. This simultaneous pressing down of the rear legs and lifting up of the opposite end of the mast decreases the lifting load that otherwise would be required for raising the mast from it prone position. Seats 1 keep the mast from slipping rearwardly along the base during this first period of its elevation.

As soon as the rear legs of the mast engage the base, their lower ends are pivotally connected to brackets 21 mounted on the base, as shown in Fig. 2. It will be noted that by this time the sling and lead line have acquired positions that are more favorable for lifting the mast than when it was fully reclined. Further reeling in of the lead line causes the mast to pivot in brackets 21 and to raise its front side from seats I on the base, as shown in broken lines in Fig. 2. The mast continues to swing upwardly in this manner until it is in upright position. The pivoted front extension legs 6 of the mast are then swung forwardly and outwardly, as shown in Figs. 3 and 4, and detachably connected to brackets 28 mounted on the base behind seats I. The legs support the mast in its upright position until it is desired to dismantle it for transportation to a new location. 7

To lower the mast, the elevating procedure just outlined is reversed. That is, the extension legs of the mast are first disconnected from the base and moved back out of the way, and then the mastis let down by the lead line and sling to the inclined position shown in Fig. 2 in which the lower ends of the stationary front legs rest in seats I. The rear legs of the mast are disconnected from brackets 21, and the mast is then allowed to rock forward until it rests upon the ground.

If the mast, as shown in Fig. 1, were turned used without excessive load on the sling and lead pended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. The method of elevating on a base a mast having at one side a stationary pair of legs that terminate short of the lower ends of its opposite pair of legs, comprising laying the mast. along the ground with the lower end portion of its short leg side on the base, swinging the top of the mast upwardly to rock the mast vertically on said lower end portion until the lower ends of said opposite pair of legs descend to the base, pivotally supporting said lower ends on the base, raising the top of the mast to lift said lower end portion from the base and to swing the mast into upright position, and then supporting the mast.

in that position.

2. The method of elevating on a base a mast having at one side a stationary pair of legs that terminate short of the lower ends of its opposite pair of legs, comprising laying the mast along the ground with the lower end portion of its short leg side on the base, lifting the top. of the mast and simultaneously pressing down on the lower ends of said oppositepair of legs to rock the mast vertically on said lower end portion until said lower ends descend to the base, pivotally supporting said lower ends on the base, raising the top of the mast to lift said lower end portion from the base and to swing the mast into upright position, and then supporting the mast in that position.

3. The method of elevating on a base a mast having at one side a stationary pair of legs pivotally connected at their lower ends to the upper ends of extension legs, comprising laying the mastalong the ground with the lower ends of said stationary legs resting on the base and with said extension legs swung out of the way, lifting the top of the mast and simultaneously pressing down on the lower ends of the opposite pair of legs to rock the mast vertically on said lower ends of said stationary legs until the lower ends of said opposite pair of legs descend to the base, pivotally supporting the lower ends of said opposite pair on the base, raising the top of the mast to lift the lower ends of 'said stationary legs from the base and to swing the mast into upright position, and then swinging said extenpressing down on the lower ends of the masts rear legs to rock the mast backwardly on said lower end of its front sideuntil the lower ends of its rear legs descend to the base, then hinging said rear legs to the base, again raising the top of the mast to lift the front of the mast from the base and to swing the mast into upright position, and then connecting said extension legs to the base to support the upright mast.

5. The method of elevating on a base a prone mast having stationary front legs pivotally connected at their lower ends to the upper ends of extension legs, comprising resting said lower ends of the prone front legs on the base with said extension legs swung out of the way, lifting the top of the mast and simultaneously pressing down on the lower ends of the masts rear legs to rock the mast backwardly on said lower ends of its front legs until the lower ends of itslrear legs descend to the base, then hinging said rear legs to the base, again raising the top of the mast to lift the front legs of the mast from the base and to swing the mast into upright position, and then swinging said extension legs forward and connecting their lower ends to the base to support the upright mast.

6. A mast structure comprising a base, a mast on the base having stationary front and rear pairs of legs, one of said pairs of legs being shorter than the other pair and having their lower ends terminating above said base when the mast is upright, means for detachably hinging the longer pair of legs to the base, releasable means for supporting the mast in upright position, means connected to the mast for swinging it between upright and prone positions, and means for pivotally supporting the short leg side of the mast on the base when the mast is inclined near prone position with said longer legs disconnected from the base, whereby the mast can be rocked on said pivoting means between prone and inclined positions.

7. A mast structure comprising a base, a mast on the base having stationary front and rear pairs of legs, one of said pairs of legsbeing shorter than the other pair and having their lower ends terminating above said base when the mast is upright, means for detachably hinging the longer pair of legs to the base, releasable means for supporting the mast in upright position, means connected to the mast for swinging it between upright and prone positions, means for pivotally supporting the short leg side of the mast on the base when the mast is inclined near prone position with said longer legs disconnected from the base, whereby the mast can be rocked on said pivoting means between prone and inclined positions, and means actuated by said mast-swinging means while the mast is being raised for pressing down on the lower ends of said longer pair of legs to aid in rocking the mast on said pivoting means until the lower ends of said longer legs descend to the base.

8. A mast structure comprising a base, a mast on the base having stationary front and rear pairs of legs, one of said pairs of legs being shorter than the other pair and having their lower ends terminating above said base when the mast is upright, means for detachably hinging the longer pair of legs to the base, means for detachably connecting the shorter pair of legs to the base to support the mast in upright position, means connected to the mast for swinging it between upright and prone positions when said shorter legs are disconnected from the base, and means for pivotally supporting the short leg side of the mast on the base when the mast is inclined near prone position with said longer legs disconnected from the base, whereby the mast can be rocked on said pivoting means between prone and inclined positions.

9. A mast structure comprising a base, a mast on thebase having stationary front and rear pairs of legs, one of said pairs of legs being shorter than the other pair and having their lower ends terminating above said base when the mast is upright, means for detachably hinging the longer pair of legs to the base, extension legs detachably connecting the shorter pair of legs to the base when the mast is in upright position, said extension legs being adapted to be moved out of the way when the mast is being raised and lowered, means connected to the mast for swinging it between upright and prone positions when said extension legs are released, and

means for pivotally supporting the short leg side of the mast on the base when the mast is inclined near prone position with said longer legs disconnected from the base, whereby the mast can be rocked on said pivoting means between prone and inclined positions.

10. A mast structure comprising a base, a mast on the base having stationary front and rear pairs of legs, one of said pairs of legs being shorter than the other pair and having their lower ends terminating above said base when the mast is upright, a gin pole mounted on the base adjacent the long leg side of the mast and having front and rear pairs of legs pivotally con-. nected together at the top, means hinging one of said pairs of gin pole legs to the base, means hinging the other pair of gin pole legs to the lower ends of the masts longer pair of legs, means for detachably hinging said lower ends of said longer legs to the base, releasable means for suporting the mast in upright position, cable means connected to the top of the gin pole and extending into the mast and then upwardly through it and out its upper end, means connected to the end of the cable means which extends out of the upper end of the mast for reeling said end to swing the mast between upright and prone positions, and means for pivotally supporting the short leg side of the mast on the base when the mast is inclined near prone position with said longer legs disconnected from the base, whereby the mast can be rocked on said pivoting means between proneand inclined positions.

11. A mast structure comprising a base, a mast on the base having stationary front and rear pairs of legs, one of said pairs of legs being shorter than the other pair and having their lower ends terminating above said base when the mast is upright, a gin pole mounted on the base adjacent the long leg side of the mast and having front and rear pairs of legs pivotally connected together at the top, means hinging one of said pairs of gin pole legs to the base, means hinging the other pair of gin pole legs to the lower ends of the masts longer pair of legs,

' detachably connecting the mast's shorter pair of legs to the base when the mast is in upright position, said extension legs being adapted to be moved out of the way when the mast is being raised and lowered, cable means connected to the top of the gin pole and extending into the mast and then upwardly through it and out its upper end, means connected to the end of the cable means which extends out of the upper end of the mast for reeling said end to swing the mast between upright and prone positions when said extension legs are released, and means for pivotally supporting the lower end of the short leg side of the mast on the base when the mast is inclined near prone position with said longer legs disconnected from the base, whereby the mast can be rocked on said pivoting means between prone and inclined positions.

12. A mast structure comprising a base, a mast on the base and having stationary front legs pivotally connected at their lower ends to the upper ends of extension legs, means for detachably hinging the rear legs of the mast to the base, means for detachably connecting said extension legs to the base when the mast is in upright position, means connectedto the upper part of the mast for swinging it between upright and prone positions when said extension legs are disconnected from the base, means for pivotally supporting the front of the mast on the base when the mast is near prone position with its rear legs disconnected from the base, whereby the mast can be rocked on said pivoting means between prone and inclined positions, and means actuated by said mast-swinging means while the mast is being raised for pressing down on the lower ends of the rear legs to I aid in rocking the mast backwardly on said pivoting means until the lower ends of the rear legs descend to the base.

13. A mast structure comprising a base, a mast on the base and having stationary front legs pivotally connected at their lower ends to the upper ends of extension legs, a gin pole mounted on the base behind the mast and having front and rear legs connected together at the top, means hinging the rear gin pole legs to the base, means flexibly connecting the front gin pole legs to the lower ends of the masts rear legs, means for detachably hinging said lower ends and means for pivotally supporting the front of the mast on the base when the mast is near prone position with its rear legs disconnected from the base, whereby the. mast can be rocked on said pivoting means between prone and inclined positions.

14. A mast structure comprising a base, a mast on the base and having stationary front legs pivotally connected at their lower ends to the upper ends of extension legs, a gin pole mounted on the base behind the mast and having front and rear legs pivotally connected together at the top, means hinging the rear gin pole legs to the base, means hinging the front gin pole legs to the lower ends of the mast's rear legs, means for detachably hinging said lower ends of the rear legs to the base, means for detachably connecting said extension legs to the base when the mast is in upright position, a cable connected to the upper part of the mast and adapted to pass over the top of the gin pole, means for reeling the cable to swing the mast between upright and prone positions when said extension legs of the mast are disconnected from the base, and means for pivotally supporting the lower end of the front side of the mast on the base when the mast is near prone position with its rear legs disconnected from the base, whereby the mast can be rocked on said pivoting means between prone and inclined positions.

15. A mast stucture comprising a base, a mast 'on the base and having stationary front legs pivotally connected at their lower ends to the upper ends of extension legs, a. gin pole mounted on the base behind the mast and having front and rear legs connected together at the top, means hinging the rear gin pole legs to the base, means flexibly connecting the front gin pole legs to the lower ends of the masts rear legs, means for detachably hinging said lower ends of the rear legs to the base, means for detachably connecting said extension legs to the base when the mast is in upright position, cable means connected to the top of the gin pole and of the rear legs to the base, means for detachbetween upright and prone positions when said extension legs are disconnected from the base,

- extending into the mast and then upwardly through it and out its upper end, means connected to the end of the cable means which extends out of the upper end of the mast for reeling said end to swing the mast between upright and prone positions when said extension legs are disconnected from the base, and means for pivotally supporting the front of the mast on the base when the mast is near prone position with its rear legs disconnected from the base, whereby the mast can be rocked on said pivoting means between prone and inclined positions.

HOMER J. WOOLSLAYER.

ERWIN A. CAMPBELL.

CECIL JENKINS. 

